Pet bottle

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PET non-returnable bottle
Half of a mold for the stretch blow molding process

PET bottles are containers made of polyethylene terephthalate that are manufactured from a PET blank using a thermal process and have been used in the beverage industry since the late 1980s, among other things, as a packaging means with screw caps , and more rarely with swing caps . In countries with a returnable deposit system that also takes plastic bottles into account, such as the returnable deposit system in Germany, there are both non-returnable and returnable PET bottles, which are significantly thicker-walled and more stable than non -returnable bottles and therefore only need to be replaced after around 20-25 returns.

history

1987: Berthold Beitz ( Krupp GmbH ), Günter Mittag and Ewald Moldt ( GDR ) with PET bottles at the Hanover Fair

The development of the PET bottle goes back to the late 1960s. At DuPont in the USA, researcher Nathaniel Wyeth further developed PET, which had been known since the 1930s, and made it possible to use it as a malleable material. In addition, machine manufacturers such as the American manufacturer Cincinnati Milacron and the German machine builder Bekum Maschinenfabriken, Berlin , as well as Heidenreich & Harbeck (later Gildemeister AG ) in Hamburg began to design high-performance machines ( extruders ) for the production of plastic bottles.

With the introduction of a 2 liter bottle by Coca-Cola in the USA in 1978 , the PET bottle started its career worldwide. This PET bottle was equipped with a bottom shell made of a different plastic material, so that the stability of the bottle at an internal pressure of 5 bar was ensured despite the then unstructured bottom shape. PET bottles were first introduced in Germany around 1987 by Coca-Cola GmbH in the form of a 1.5 liter one-way bottle known as a "one-fiver". In 1990, the self-advertised "unbreakable" 1.5-liter returnable PET bottle followed, also with a 1.5-liter content.

By the early 1990s, the technology to make one-piece bottles made from only PET was mature and available in the market. This fact and the shortened requirements for the shelf life of beverages resulted in the spread of the PET bottle on the markets. Through technical developments in the production of PET bottles, quality improvements have been implemented (e.g. coating processes, production processes for the production of the lightest possible bottles or for the hot filling of juice products), as well as higher productivity in production, more economical use of the raw material PET and Enables energy savings in production. In addition, the weight of comparable PET bottles could in some cases be reduced considerably, depending on the volume and intended use (one-way, returnable bottle, hot filling). The weight of non-returnable PET bottles has been reduced from originally around 50 to 80 g to the current weight of around 12 to 35 g. The returnable PET bottles used since the early 1990s are heavier for reasons of stability. A 1.5-liter returnable Coca-Cola bottle used in Germany now weighs around 112 g, for example.

The percentage of PET bottles in the packaging mix in 2010 was 34% worldwide. In Germany, PET bottles in sizes from 0.3 to 5.0 liters are in circulation as non-returnable and returnable bottles and are now much more widely used for filling carbonated soft drinks than the traditional glass bottle (especially the standard fountain bottle ). In the meantime, other drinks such as juices, nectars and, to a lesser extent, beer are also bottled in PET bottles.

Manufacturing

PET bottle and blank
Injection blow molding process
Stretch blow molding machine with preform infeed (right), heating furnace (right behind), blowing wheel (center) and bottle delivery to the transport device (left)
PET blanks before inflation

The basis for the production of PET bottles is the thermoformability of the base material, polyethylene terephthalate. The PET bottle is produced in two process steps:

These two manufacturing steps can be implemented directly in the plastics processing company in a one-step process (injection stretch blow molding) so that the finished PET bottles can then be delivered to the beverage company. This procedure is also described as “first heat process”.

The far more common case is the two-stage process with a separation of the injection molding process from the stretch blow molding process (process using second heat). The blanks are manufactured by a plastics processor and delivered to the beverage companies, where the PET bottles are produced in their own stretch blow molding machine. The advantage of this procedure is that the different process times for the production of blanks and for the production of PET bottles do not have to be coordinated with one another. In addition, there is greater flexibility in the choice of blank types and weights. The lower transport costs for PET blanks between the plastics processor and the beverage company also speak in favor of the two-stage process.

In most countries, antimony trioxide is used as a catalyst in PET production, which can be detected in small traces in bottled beverages. The limit values ​​for antimony recommended in the drinking water regulations of various countries are, however, significantly higher than the antimony content of the beverages tested.

Since PET bottles are sensitive to heat and therefore cannot be made sterile using thermal sterilization processes, chemical sterilization is required, such as B. the DS process .

advantages

SODIS application example from Indonesia

For the consumer, PET bottles are easy to use because they are lightweight and not prone to breakage. The low weight also results in lower transport energy consumption.

PET bottles containing unlike many beverage bottles made of other plastics No deleterious bisphenol A . Despite the designation "polyethylene tere phthalate " (PET), PET bottles do not contain any plasticizers in the form of phthalates , which can function as xenohormones .

PET bottles are suitable for SODIS , a simple but effective method for water disinfection. SODIS stands for Solar Water Disinfection and is based on the germicidal effect of UV-A radiation in sunlight. The WHO recommends SODIS as an effective method for treating water at the household level. SODIS is used in an increasing number of households in numerous developing countries .

disadvantage

Cold disinfection

In order to fill PET bottles aseptically, the liquid to be filled cannot be filled hot, as is usual with glass bottles. The so-called cold sterilization with the help of dimethyl dicarbonate (DMDC) is used here. DMDC disintegrates completely in beverages due to its water content. Small amounts of methanol and carbon dioxide are produced as degradation products. These substances are u. a. natural components of fruit-based beverages and wine.

If ammonium ions (NH 4 + ) are present in beverages and it is an aqueous-acidic solution, very small amounts of O-methyl carbamate (O-methyl urethane ) can form. This substance has been detected in wines that have been sterilized with dimethyl dicarbonate (DMDC). It's on the California State's List of Carcinogens. O-methyl carbamate has been well studied toxicologically and it has been shown that it can only promote liver cancer in female rats of a certain rat strain (F344) at very high levels of exposure (200 mg / kg body weight / day for 103 weeks daily). This effect could not be observed either in another strain of rats (Wistar) or in mice.

According to its report from 2015, the European Food Safety Authority (EFSA) sees no evidence of a health risk in the context of approved use in beverages in the case of cold sterilization with DMDC.

Gas leak

In contrast to glass, PET is not gas-tight. Since carbon dioxide from the PET bottle diffuses out , some beverages can already after a few weeks will be stale and inedible; penetrating oxygen leads to changes in taste and possibly to spoilage of the contents. Because this phenomenon decreases with increasing vessel size (→  A / V ratio ), the thin-walled one-way bottles, especially for carbonated beverages, are usually only available in sizes over one liter. Mineral water and other carbonated drinks in PET bottles have a significantly shorter specified shelf life (approx. 40–50%) than those in glass bottles and beverage cans. Plasma coatings with silicon dioxide on the inside or outside can significantly improve gas tightness.

acetaldehyde

Since the PET plastic releases smaller amounts of wine- smelling, harmful acetaldehyde (ethanal) into the liquid, PET bottles were initially only filled with sweet drinks that masked the aftertaste. The PET bottle manufacturers state that they have got this odor problem under control. The Federal Institute for Risk Assessment (BfR) considers the concentration of acetaldehyde in PET bottles to be harmless as it is below the legal limit. Nevertheless, this substance, which z. B. can lead to cirrhosis of the liver , detectable in PET bottles. Acetaldehyde is also a natural component of fruits and other foods like cheese; In some cases, the substance occurs there in significantly higher concentrations than in the mineral water from PET bottles.

Even before these phenomena were classified by the Federal Institute for Risk Assessment (BfR), processes were developed to coat the inside of the PET bottles with an SiO 2 layer with a thickness in the nanometer range . However, these are currently not being implemented by industry for reasons of cost.

Microplastics

New studies by the Chemical and Veterinary Investigation Office Münsterland-Emscher-Lippe in collaboration with the University of Münster show that microplastics from packaging material get into mineral water and thus directly into the human food chain. Most of the particles found in the returnable PET bottles were identified as polyethylene terephthalate (PET, 84%) and polypropylene (PP; 7%). The returnable bottles are made of PET and the lids are made of PP. Only a few PET particles were found in the water in the non-returnable PET bottles. Other polymers such as polyethylene and polyolefins were found in the water in the beverage cartons and glass bottles . This is explained by the fact that beverage cartons are coated with polyethylene films and closures are treated with lubricants. Therefore, these results suggest that the packaging itself can release microparticles.

Possible hormonally active substances from PET bottles

Although PET does not contain bisphenol A or orthophthalates (see phthalic acid esters ), significant estrogen-like effects of PET were found in two specialist articles published by the same researchers at the Johann Wolfgang Goethe University in Frankfurt am Main in 2009 and 2011, respectively . The subject of these articles are studies in which the hormonal effects of water on human cells were examined and compared to what was previously stored in either glass or PET bottles. However, these results could not be reproduced by other researchers. The Federal Institute for Risk Assessment (BfR) was also unable to understand the results of the Frankfurt researchers. It could not determine any connection between PET bottles and the contamination of mineral water with estrogen-like active substances and sees "no need for consumers to forego mineral water from PET bottles."

recycling

Non-returnable PET bottles are collected and partly recycled , partly "thermally recovered", that is, they are used as fuel in waste incineration plants or thermal power stations .

In processing plants, the PETs are chopped into small flakes, cleaned of foreign matter, sorted by color and processed into granules. Some of this material can be added to the virgin material and used to manufacture new preforms in an injection molding process for beverage bottles. The production of new (crystal clear or pure color) bottles exclusively from recycled material has not been possible until now. German and US chemists have now developed two processes that will be able to recycle 100 percent of PET bottles in the future. In the first process, the previously mechanically shredded material is chemically dissolved, filtered and precipitated again; in the second process, the material is converted back into pure PET with the help of heat and a catalyst.

Second- hand PET is also used to manufacture polyester textile fibers . China is the world market leader in this field . In 2006 alone, almost four million tons of PET waste were exported to China, which corresponds to around 100 billion plastic bottles. Turkey also imports old PET to make textile fibers from it. The market value of single-origin PETs is between 400 and 500 euros per ton. The material value of a used 1.5-liter disposable bottle is therefore around 1.5 euro cents. As early as the 1990s, the market value of recycled PET (flakes) was based 100 percent on the cost of the raw materials terephthalic acid and ethylene glycol it contained . Therefore it was not possible to use it in the chemical industry as a raw material substitute for terephthalic acid / glycol. At the beginning of 2018, China stopped importing plastic waste. The import ban also affects other waste such as electronic waste , waste paper and slag from the iron and steel industry . The government in Beijing justifies the ban with the protection of the environment and health .

Germany

Due to the deposit regulation in Germany , a large part of the PET bottles is recycled via the empties collection points. About 30% of the PET bottles end up in a "single-type material cycle". According to a market analysis by the GVM Society for Packaging Market Research, 93.6% of PET beverage bottles are recycled in Germany. The recycling balance for PET bottles subject to a deposit is 97.2%. Around 80% of PET recycling takes place within Germany, only a small part is recycled abroad. Around a third of the PET recyclates produced domestically were used in 2013 for the production of new PET beverage bottles. Other customers are the textile fiber industry (29%), the film industry (27%) and other applications such as tapes or detergent bottles (11%). In 2013, an average of 24% of new PET beverage bottles consisted of recycled material (26% of the non-returnable bottles subject to a deposit). Since September 2018, the Berlin-based start-up company share GmbH has been the first manufacturer in Germany to only market water bottles made from fully recycled plastic (100%).

Austria

Around 7,000 t of PET were used in Austria in 1996; in 2002 the market volume was around 26,800 t. In 2003 it reached the record level of around 33,700 t. In 2004 it was even higher, namely at approx. 33,800 t, in the following year 2005, taking into account the so-called two-way systems , it rose to approx. 36,400 t. In 2006 the market volume reached approx. 39,000 t and finally 40,500 t in the 2007 reporting year. The PET to PET Recycling Austria GmbH - a company of producers Group Coca-Cola Hellenic Austria, Radlberger drinks, smoke fruit juices, Spitz and Vöslauer. Other recycling plants: PET Recycling Team GmbH and Kruschitz GmbH. In the PET to PET facility in Müllendorf, Burgenland, around 43,964 tons of PET material have been processed back into raw material for new PET bottles and other food packaging since it was commissioned in August 2007. After recycling at PET to PET, the processed material is available to all companies in the beverage industry that meet the requirements of the sustainability agenda. The quantities are based on the percentage of their "placed on the market" (according to ARA statistics), that is, the more bottles a company puts into circulation through retailers, the larger the quantities of processed material are available to the beverage manufacturer.

Switzerland

Response rates

Germany

The number of PET bottles in circulation in Germany in 2003 was estimated to be around 800 million in size units of 1.5 liters, 1 liter and 0.5 liters. With the introduction of the mandatory deposit on defined one-way beverage packaging on January 1, 2003, there was a sharp increase in the quantities in circulation. Before this cut-off date, the “ dual system ” recycled around 99% of the PET bottles collected, which corresponded to around half of the total bottles produced. Since the beginning of 2003, around 70% of German PET bottles have been taken back directly from the sales outlets. There is currently no reliable information about the current quantities in circulation.

Austria

In Austria, light packaging and PET bottles are collected, sorted and recycled by the Austrian collection and recycling systems for packaging. Households and businesses are supplied via the nationwide, licensed systems (collection, sorting and recycling of packaging waste).

Switzerland

In Switzerland , the "return and return of beverage packaging for domestic use" is regulated in the Ordinance on Beverage Packaging (VGV) of July 5, 2000 issued by the Federal Council . According to this, dealers, manufacturers and importers who dispense the beverages in disposable PET packaging must also take back such disposable packaging in all sales outlets. The recycling rate should be at least 75%. If this is not achieved, the Federal Department of the Environment, Transport, Energy and Communication can introduce a deposit on PET beverage packaging.

The PRS PET-Recycling Switzerland association is responsible for the comprehensive, separate collection of non-returnable PET beverage bottles . This operates a nationwide collection point network of over 50,000 collection points, 9,000 of which are located directly at the sales points and 41,000 at voluntary collection points for work and leisure.

In 2016, the return rate with a consumption of 1.6 billion PET bottles was 82% (see also bottle deposit # recovery rate ).

Impact on the environment

Since PET bottles are often used to fill drinking water and soft drinks (63% of all beverage bottles in Japan), and the global demand for them is very high due to drinking water pollution, such bottles make up a large part of household waste. In Austria - according to a publication from 2011 - an average of 26 percent of PET bottles remain in household waste, in large cities even more, in Europe only 48.4 percent of PET bottles are collected. Uncompressed plastic bottles in household waste greatly increase the volume of waste, which means that landfills (in countries where residual waste is still dumped) are filled faster.

Stranded goods on the Upper Guinea coast of West Africa: almost exclusively PET drinks bottles

Especially in developing countries , the waste disposal is often via rivers, and all materials with a lower density than fresh water or sea water , including PET bottles include, swim as driftwood and plastic debris in the oceans or deface as garbage flotsam the coasts and beaches.

Textile fibers from recycled PET bottles are also suspected of contributing to the problem of plastic waste in the microparticle area through abrasion during washing. According to a study published in the journal Environmental Science & Technology , washing machines rub off more than 1,900 microparticles - less than a millimeter in diameter - from fleece fabrics made of polyester and acrylic textile fibers per wash cycle . They are not held back in sewage treatment plants. If these microparticles get into the sea via sewage, they form part of the plastic waste in the oceans. Such particles were found in the sediment of 18 beaches worldwide, not a single sample was free of them.

PET as an inner sleeve for high pressure gas bottles

The development of light gas cylinders for respiratory protection (fire brigade), helium balloons, vehicle fuel gases as well as flight, space travel and emergency applications led from

  • Type 1 - made of metal only (seamless; steel or aluminum alloy), about
  • Type 2 - metal bottles wrapped with fibers only on the cylindrical circumference and
  • Type 3 - bottles with a thin metal liner, which is completely wrapped , for
  • Type 4 - bottles in which the liner , the gas-tight inner layer, is made of plastic . Only the neck is made of metal, sometimes also a bottom piece.

The plastic liner of these type 4 composite bottles was initially made from HDPE . In 2014 the PET bottle blow molding machine manufacturer SIPA developed a process for the precise blowing of PET liners for the gas bottle manufacturer CTS (both based in Italy). PET holds oxygen much better, because the permeability of PE is 40 to 100 times greater (at 300 bar). This bladder can be made thinner and therefore light from PET; it also serves as a core for the CNC -Bewicklung with carbon fiber - roving . The fibers are fixed with epoxy resin as a matrix.

This construction, patented for CTS - type 4 with PET liner - results in today's lightest vessels for operating pressures in the range from 100 to 800 bar.

Web links

Wiktionary: PET bottle  - explanations of meanings, word origins, synonyms, translations
Commons : PET Bottles  - Collection of Images

Individual evidence

  1. ↑ suedglas.de: PET bottle with swing top ( Memento from December 27, 2014 in the Internet Archive ).
  2. ^ MIT website, Inventor of the Week: Nathaniel Wyeth. The plastic soda bottle ( Memento from June 13, 2012 in the Internet Archive )
  3. ^ O. Brandau: Stretch Blow Molding, A Hands-on Guide. Heidelberg 2003, ISBN 3-9807497-2-X .
  4. ^ The Coca-Cola Company: History of Packaging Innovation .
  5. ↑ Coca-Cola-Dosen.de: Old sticker for the market launch of the "Einsfünfer" (with Fanta design from 1987).
  6. ^ Nina Janich: Advertising language. A work book. 2nd Edition. Narr, Tübingen 2001, p. 106. ISBN 3-8233-4974-0
  7. ↑ neue-verpackung.de: The weight of PET bottles continues to decrease in France. .
  8. ↑ Beverage Packaging Reverting to Trend? ( Memento from November 18, 2011 in the Internet Archive )
  9. ^ Walter Michaeli , Introduction to Plastics Processing, Hanser, Munich, 2010, ISBN 978-3-446-42488-3 , p. 112.
  10. ↑ Michael Thielen, Klaus Hartwig, Peter Gust: Blow molding of hollow bodies, Hanser, Munich 2006, ISBN 3-446-22671-0 , p. 149.
  11. ↑ ibid. P. 211.
  12. ↑ "Mineral water from PET bottles is contaminated with antimony" (Science Information Service, January 24, 2006).
  13. ↑ BfR Bund - Do PET bottles contain bisphenol A? ( Memento from June 25, 2009 in the Internet Archive ).
  14. ↑ BfR Bund - Do PET bottles contain plasticisers? .
  15. ↑ Vol. 58, Federal Register 1993, page 6088 ff.
  16. ↑ http://www.inchem.org/documents/jecfa/jecmono/v28je15.htm
  17. ↑ CHEMICALS KNOWN TO THE STATE TO CAUSE CANCER OR REPRODUCTIVE TOXICITY - February 3, 2006 ( Memento of May 12, 2006 in the Internet Archive ).
  18. ↑ https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2015.4319
  19. ↑ https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2015.4319
  20. ↑ Julia Weiler: Plasma coating: how fewer gases get through the plastic layer - a touch of glass makes you leakproof. In: Medizin-und-technik.de. February 12, 2015, archived from the original on August 30, 2016 ; accessed on August 30, 2016 .
  21. ↑ BfR on the acetaldehyde concentration in PET bottles ( Memento from June 22, 2011 in the Internet Archive ) (English).
  22. ↑ FAQ on PET beverage bottles (Forum PET). Retrieved May 18, 2016 .
  23. ↑ "A research result goes around the world: Physicists developed a new bottle for Coca Cola" (status: May 18, 2000).
  24. ↑ "Researchers make PET bottles sterile and tight" (pressetext austria, February 25, 2006).
  25. ↑ Darena Schymanski, Christophe Goldbeck, Hans-Ulrich Humpf, Peter Fürst: Analysis of microplastics in water by micro-Raman spectroscopy: Release of plastic particles from different packaging into mineral water . In: Water Research . tape 129 , 2018, p. 154–162 , doi : 10.1016 / j.watres.2017.11.011 .
  26. ↑ M. Wagner, J. Oehlmann: Endocrine disruptors in bottled mineral water: estrogenic activity in the E-Screen. In: The Journal of steroid biochemistry and molecular biology. Volume 127, Number 1-2, October 2011, pp. 128-135, ISSN  1879-1220 . doi : 10.1016 / j.jsbmb.2010.10.007 . PMID 21050888 . (Complete article as Endocrine disruptors in bottled mineral water: Estrogenic activity in the E-Screen or Endocrine disruptors in bottled mineral water: Estrogenic activity in the E-Screen ).
  27. ↑ Martin Wagner, Jörg Oehlmann: Endocrine disruptors in bottled mineral water: total estrogenic burden and migration from plastic bottles (abstract) In: Environmental Science and Pollution Research , Volume 16, Issue 3, 2009. pp. 278–286 (complete study as Endocrine disruptors in bottled mineral water: total estrogenic burden and migration from plastic bottles ).
  28. ↑ Interview with Dr. Frank Welle, Fraunhofer Institute for Process Engineering and Packaging: No hormones from PET In: Stiftung Warentest , Natural mineral water: 30 medium mineral waters in the test , June 28, 2017, last accessed on August 4, 2017
  29. ↑ Hormonally acting substances in mineral water from PET bottles . Information No. 006/2009 of the BfR from March 18, 2009 on a study by the University of Frankfurt am Main. (PDF; 72 kB).
  30. ↑ Jackets made from plastic bottles at www.tagesspiegel.de.
  31. ↑ This sweater was once a bottle in the Hamburger Abendblatt.
  32. ↑ Jan Garvert , tagesschau.de: Who benefits from the recycling bin? ( Memento of July 14, 2014 in the Internet Archive ), July 11, 2014.
  33. ↑ Limits of recycling - Germany is sinking into plastic waste In: faz.net , January 5, 2018, accessed on January 11, 2018.
  34. ↑ Beverage bottles made of PET - masters of recycling: IK Industrievereinigung Kunststoffverpackungen eV Accessed on June 27, 2016 .
  35. ↑ Marcel Rosenbach, Simone Salden: The fight against plastic waste: Share brings the first fully recycled water bottle onto the market . In: Spiegel Online . September 14, 2018 ( spiegel.de [accessed January 21, 2019]).
  36. ↑ "Implementation Report of the Austrian Beverage Industry 2008 pdf" Implementation Report 2007 - Austrian Chamber of Commerce (June 2008) ( Memento from December 3, 2013 in the Internet Archive ).
  37. ^ Ordinance on beverage packaging (VGV) of July 5, 2000 .
  38. ^ Website of the PRS PET Recycling Switzerland Association , January 29, 2018.
  39. ↑ The waste export business
  40. ↑ UNICEF For the children's right to water , For the children's right to water ( Memento from July 23, 2013 in the Internet Archive )
  41. ↑ Beverage packaging on the test stand, Vienna, 2011, the environmental advice service Beverage packaging on the test stand - Sustainable beverage consumption: Reusable drinks win , the environmental advice is carried out by VHS Vienna, see imprint "die Umweltberatung"
  42. ↑ Julia Schilly: Six times more plastic than plankton in the world's oceans derstandard.at, June 8, 2011.
  43. ↑ Danger from microplastic waste orf.at, December 22, 2012, last accessed September 19, 2017.
  44. ↑ Mark Anthony Browne, Phillip Crump, Stewart J. Niven, Emma Teuten, Andrew Tonkin, Tamara Galloway, Richard Thompson: Accumulation of Microplastic on Shorelines Worldwide: Sources and Sinks , Environment Science & Technology, 2011, 45 (21), pp. 9175 -9179, doi : 10.1021 / es201811s
  45. ↑ Sipa Helps Lightweight Composite Technical Cylinders Work Under Pressure ( Memento from November 8, 2016 in the web archive archive.today ) packagingeurope.com, October 30, 2014, accessed on November 7, 2016.